Movie S3.

Controlled lysis of individual diatoms to create DOM hotspots. A chain of C. affinis is shown in time-lapse images captured each 15 s via phase microscopy (Left) and epifluorescence microscopy (Right). Time labels denote hours:minutes:seconds. Before image capture, the diatom had been exposed to continuous fluorescent light for ∼5 min to stimulate cell lysis. Plasmolysis was confirmed by the intracellular accumulation of a polar fluorescent dye (SYTOX Green) that permeates compromised cell membranes (at 00:02:00 and again at 00:31:30). For this visualization, no bacteria were added and small particles were inherent to the diatom culture media. A subset of images from this movie are shown in Fig. S2. (Scale bar, 50 μm.)